Responses of pulvinar neurons reflect a subject's confidence in visual categorization

• Published in: Nature neuroscience Vol. 16; no. 6; pp. 749 - 755
• Main Authors: Komura, Yutaka, Nikkuni, Akihiko, Hirashima, Noriko, Uetake, Teppei, Miyamoto, Aki
• Format: Journal Article
• Language: English
• Published: New York Nature Publishing Group US 01.06.2013; Nature Publishing Group
• Subjects: 631/378/2649; Animal Genetics and Genomics; Animals; Attention - physiology; Awareness - physiology; Behavioral Sciences; Biological Techniques; Biomedicine; Confidence; Decision Making - physiology; Electrodes, Implanted; Genetic aspects; Geniculate Bodies - physiology; Macaca; Male; Models, Neurological; Monkeys & apes; Neurobiology; Neurons; Neurons - physiology; Neuropsychological Tests; Neurosciences; Physiological aspects; Primates; Problem Solving - physiology; Pulvinar - cytology; Pulvinar - physiology; Pulvinar - surgery; Visual cortex; Visual Perception - physiology; Japan
• ISSN: 1097-6256; 1546-1726; 1546-1726
• DOI: 10.1038/nn.3393

Here the authors report evidence for the neural correlates of confidence in the primate pulvinar, a visual thalamic nucleus. Data from electrophysiological recordings, functional silencing and theoretical modeling indicate that pulvinar activity encodes a subject's certainty of visual categorization and contributes to perceptual confidence, which potentially underlies visual awareness. When we recognize a sensory event, we experience a confident feeling that we certainly know the perceived world 'here and now'. However, it is unknown how and where the brain generates such 'perceptual confidence'. Here we found neural correlates of confidence in the primate pulvinar, a visual thalamic nucleus that has been expanding markedly through evolution. During a categorization task, the majority of pulvinar responses did not correlate with any 'perceptual content'. During an opt-out task, pulvinar responses decreased when monkeys chose 'escape' options, suggesting less confidence in their perceptual categorization. Functional silencing of the pulvinar increased monkeys' escape choices in the opt-out task without affecting categorization performance; this effect was specific to the contralateral visual target. These data were supported by a theoretical model of confidence, indicating that pulvinar activities encode a subject's certainty of visual categorization and contribute to perceptual confidence.